Microvascular research最新文献

Ischemic stroke occurs due a blockage in the blood flow to the brain, leading to damage to the nervous system. The prevalent morbidities resulting from stroke include post-stroke infection, as sepsis. Additionally, oxidative stress is recognized for inducing functional deficits in peripheral organs during sepsis. Therefore, sex differences in stroke exist and we aimed to investigate the peripheral oxidative stress caused by sepsis after stroke in male and female rats. Wistar rats (male and female) were divided into sham+sham, middle cerebral artery occlusion (MCAO) + sham, sham+ cecal ligation and perforation (CLP) and MCAO+CLP groups to males and female rats. Animals were subjected to MCAO or sham and after 7 days, were subjected to sepsis by CLP or sham. After 24 h, serum, total brain, lung, liver, heart, and spleen were collected. Brain edema, myeloperoxidase (MPO) activity, nitrite/nitrate (N/N) concentration, oxidative damage to lipids and proteins, and catalase activity were evaluated. Brain edema was observed only in male rats in MCAO+CLP group compared to MCAO+sham. Regarding MPO activity, an increase was verified in male in different organs and serum in MCAO+CLP group. For N/N levels, the increase was more pronounced in females submitted to MCAO+CLP. In general, to oxidative stress, an increase was only observed in animals exposed to MCAO+CLP, or with a greater increase in this group compared to the others. The findings provided the first indication that animals exposed to MCAO exhibit a heightened vulnerability to the harmful impacts of sepsis, as evidenced by brain edema and peripheral oxidative stress, and this susceptibility is dependent of sex.

Vincristine (VCR), a vinca alkaloid with anti-tumor and anti-oxidant properties, is acclaimed to possess cardioprotective action. However, the molecular mechanism underlying this protective effect remains unknown. This study investigated the effects of VCR on isoprenaline (ISO), a beta-adrenergic receptor agonist, induced cardiac hypertrophy in male Wistar rats. Animals were pre-treated with ISO (1 mg/kg) intraperitoneally for 14 days before VCR (25 μg/kg) intraperitoneal injection from days 1 to 28. Thereafter, mechanical, and electrical activities of the hearts of the rats were measured using a non-invasive blood pressure monitor and an electrocardiograph, respectively. After which, the heart was homogenized, and supernatants were assayed for contractile proteins: endothelin-1, cardiac troponin-1, angiotensin-II, and creatine kinase-MB, with markers of oxidative/nitrergic stress (SOD, CAT, MDA, GSH, and NO), inflammation (TNF-a and IL-6, NF-kB), and caspase-3 indicative of VCR reduced elevated blood pressure and reversed the abnormal electrocardiogram. ISO-induced increased endothelin-1, cardiac troponin-1, angiotensin-II, and creatine phosphokinase-MB, which were reversed by VCR. ISO also increased TNF-α, IL-6, NF-kB expression with increased caspase-3-mediated apoptosis in the heart. However, VCR reduced ISO-induced inflammation and apoptosis, with improved endogenous antioxidant agents (GSH, SOD, CAT) relative to ISO controls. Moreso, VCR, protected against ISO-induced histoarchitectural degeneration of cardiac myofibre. The result of this study revealed that VCR treatment significantly reverses ISO-induced cardiac hypertrophic phenotypes, via mechanisms connected to improved levels of proteins involved in excitation-contraction, and suppression of oxido-inflammatory and apoptotic pathways.

Prior work has yet to determine whether the reduction of dietary nitrate (NO₃⁻) to NO, via the enterosalivary pathway, may modify cutaneous vascular conductance (CVC) responses to local heating in older women. Changes occurring with the transition to menopause related to hormonal flux, increased adiposity, and/or decreased physical activity may further compound the negative influence of aging on nitric oxide (NO)-dependent CVC. Herein, we characterized changes in NO-dependent CVC following acute ingestion of 140 mL of NO₃⁻-rich beetroot juice in 24 older women (age: 65 ± 5 y, BMI: 31.2 ± 3.7 kg/m²). Red blood cell (RBC) flux was measured continuously via laser-Doppler flowmetry on the dorsal aspect of the forearm during local skin heating to 39 °C/44 °C before and 3 h after NO₃⁻ ingestion. NO-dependent changes in CVC were calculated as RBC flux/mean arterial blood pressure at 39 °C and normalized as a proportion of maximal CVC at 44 °C (%CVCmax). Changes (Δ) in fractional exhaled NO (FeNO) following NO₃⁻ ingestion were used an index of NO bioavailability. Despite increased FeNO (+81 ± 70 %, P < 0.001), %CVCmax at 39 °C was reduced (−16 ± 10 %, P < 0.001) following NO₃⁻ ingestion. A greater reduction in %CVCmax was weakly to moderately associated with higher body fat% (r = 0.45 [0.05–0.72], P = 0.029), central adiposity% (r = 0.50 [0.13–0.75], P = 0.012), neutrophil% (r = 0.42 [0.02–0.70], P = 0.041), and higher neutrophil to lymphocyte ratio (r = 0.49 [0.11–0.75], P = 0.016). These findings demonstrate a single dose of dietary NO₃⁻ does not promote CVC responses to local heating in sedentary older women with overweight and obesity. Correlation with multiple biomarkers suggest systemic inflammation may be involved.

Cardiac myxoma is the most common primary cardiac tumor in adults. The histogenesis and cellular composition of myxoma are still unclear. This study aims to reveal the role of myxoma cell components and their gene expression in tumor development. We obtained single living cells by enzymatic digestion of tissues from 4 cases of surgically resected cardiac myxoma. Of course, there was 1 case of glandular myxoma and 3 cases of nonglandular myxoma. Then, 10× single-cell sequencing was performed. We identified 12 types and 11 types of cell populations in glandular myxoma and nonglandular myxoma, respectively. Heterogeneous epithelial cells are the main components of glandular myxoma. The similarities and differences in T cells in both glandular and nonglandular myxoma were analyzed by KEGG and GO. The most important finding was that there was active communication between T cells and epithelial cells. These results clarify the possible tissue occurrence and heterogeneity of cardiac myxoma and provide a theoretical basis and guidance for clinical diagnosis and treatment.

Angiogenesis is mainly regulated by the delivery of VEGF-dependent signaling to cells. However, the angiogenesis mechanism regulated by VEGF-induced miRNA is still not understood. After VEGF treatment in HUVECs, we screened the changed miRNAs through small-RNA sequencing and found VEGF-induced miR-4701-3p. Furthermore, the GFP reporter gene was used to reveal that TOB2 expression was regulated by miR-4701-3p, and it was found that TOB2 and miR-4701-3p modulation could cause angiogenesis in an in-vitro angiogenic assay. Through the luciferase assay, it was confirmed that the activation of the angiogenic transcription factor MEF2 was regulated by the suppression and overexpression of TOB2 and miR-4701-3p. As a result, MEF2 downstream gene mRNAs that induce angiogenic function were regulated. We used the NCBI GEO datasets to reveal that the expression of TOB2 and MEF2 was significantly changed in cardiovascular disease. Finally, it was confirmed that the expression of circulating miR-4701-3p in the blood of myocardial infarction patients was remarkably increased. In patients with myocardial infarction, circulating miR-4701-3p was increased regardless of age, BMI, and sex, and showed high AUC levels in specificity and sensitivity analysis (AUROC) (AUC = 0.8451, 95 % CI 0.78–0.90). Our data showed TOB2-mediated modulation of MEF2 and its angiogenesis by VEGF-induced miR-4701-3p in vascular endothelial cells. In addition, through bioinformatics analysis using GEO data, changes in TOB2 and MEF2 were revealed in cardiovascular disease. We suggest that circulating miR-4701-3p has high potential as a biomarker for myocardial infarction.

Exosomes are nanosized vesicles that have been reported as cargo-delivering vehicles between cells. Müller cells play a crucial role in the pathogenesis of diabetic retinopathy (DR). Activated Müller cells in the diabetic retina mediate disruption of barrier integrity and neovascularization. Endothelial cells constitute the inner blood-retinal barrier (BRB). Herein, we aim to evaluate the effect of Müller cell-derived exosomes on endothelial cell viability and barrier function under normal and hyperglycemic conditions. Müller cell-derived exosomes were isolated and characterized using Western blotting, nanoparticle tracking, and electron microscopy. The uptake of Müller cells-derived exosomes by the human retinal endothelial cells (HRECs) was monitored by labeling exosomes with PKH67. Endothelial cell vitality after treatment by exosomes under normo- and hypoglycemic conditions was checked by MTT assay and Western blot for apoptotic proteins. The barrier function of HRECs was evaluated by analysis of ZO-1 and transcellular electrical resistance (TER) using ECIS. Additionally, intracellular Ca⁺² in HRECs was assessed by spectrofluorimetry. Analysis of the isolated exosomes showed a non-significant change in the number of exosomes isolated from both normal and hyperglycemic condition media, however, the average size of exosomes isolated from the hyperglycemic group showed a significant rise when compared to that of the normoglycemic group. Müller cells derived exosomes from hyperglycemic condition media markedly reduced HRECs cell count, increased caspase-3 and Annexin V, decreased ZO-1 levels and TER, and increased intracellular Ca⁺ when compared to other groups. However, treatment of HRECs under hyperglycemia with normo-glycemic Müller cells-derived exosomes significantly decreased cell death, preserved cellular integrity and barrier function, and reduced intracellular Ca⁺². Collectively, Müller cell-derived exosomes play a remarkable role in the pathological changes associated with hyperglycemia-induced inner barrier dysfunction in DR. Further in vivo research will help in understanding the role of exosomes as therapeutic targets and/or delivery systems for DR.

Introduction

Critical illness is associated with organ failure, in which endothelial hyperpermeability and tissue edema play a major role. The endothelial angiopoietin/Tie2 system, a regulator of endothelial permeability, is dysbalanced during critical illness. Elevated circulating angiopoietin-2 and decreased Tie2 receptor levels are reported, but it remains unclear whether they cause edema independent of other critical illness-associated alterations. Therefore, we have studied the effect of angiopoietin-2 administration and/or reduced Tie2 expression on microvascular leakage and edema under normal conditions.

Methods

Transgenic male mice with partial deletion of Tie2 (heterozygous exon 9 deletion, Tie2^+/−) and wild-type controls (Tie2^+/+) received 24 or 72 pg/g angiopoietin-2 or PBS as control (n = 12 per group) intravenously. Microvascular leakage and edema were determined by Evans blue dye (EBD) extravasation and wet-to-dry weight ratio, respectively, in lungs and kidneys. Expression of molecules related to endothelial angiopoietin/Tie2 signaling were determined by ELISA and RT-qPCR.

Results

In Tie2^+/+ mice, angiopoietin-2 administration increased EBD extravasation (154 %, p < 0.05) and wet-to-dry weight ratio (133 %, p < 0.01) in lungs, but not in the kidney compared to PBS.

Tie2^+/− mice had higher pulmonary (143 %, p < 0.001), but not renal EBD extravasation, compared to wild-type control mice, whereas a more pronounced wet-to-dry weight ratio was observed in lungs (155 %, p < 0.0001), in contrast to a minor higher wet-to-dry weight ratio in kidneys (106 %, p < 0.05).

Angiopoietin-2 administration to Tie2^+/− mice did not further increase pulmonary EBD extravasation, pulmonary wet-to-dry weight ratio, or renal wet-to-dry weight ratio. Interestingly, angiopoietin-2 administration resulted in an increased renal EBD extravasation in Tie2^+/− mice compared to Tie2^+/− mice receiving PBS. Both angiopoietin-2 administration and partial deletion of Tie2 did not affect circulating angiopoietin-1, soluble Tie2, VEGF and NGAL as well as gene expression of angiopoietin-1, −2, Tie1, VE-PTP, ELF-1, Ets-1, KLF2, GATA3, MMP14, Runx1, VE-cadherin, VEGFα and NGAL, except for gene and protein expression of Tie2, which was decreased in Tie2^+/− mice compared to Tie2^+/+ mice.

Conclusions

In mice, the microvasculature of the lungs is more vulnerable to angiopoietin-2 and partial deletion of Tie2 compared to those in the kidneys with respect to microvascular leakage and edema.

Objectives

Systemic vasculitis is a heterogenous group of autoimmune diseases characterized by enhanced cardiovascular mortality. Endothelial dysfunction is associated with accelerated vascular damage, representing a core pathophysiologic mechanism contributing to excess CV risk. Recent studies have also shown that complement activation holds significant role in the pathogenesis of Anti-Neutrophilic Cytoplasmic Autoantibody (ANCA) -associated vasculitis (AAV). Given the potential crosstalk between the endothelium and complement, we aimed to assess, for the first time simultaneously, easily accessible biomarkers of endothelial dysfunction and complement activation in SV.

Methods

We measured circulating endothelial microvesicles (EMVs) and soluble complement components representative of alternative, classical and terminal activation (C5b-9, C1q, Bb fragments, respectively) in a meticulously selected group of patients with systemic vasculitis, but without cardiovascular disease. Individuals free from systemic diseases, who were matched with patients for cardiovascular risk factors(hypertension, diabetes, smoking, dyslipidemia), comprised the control group.

Results

We studied 60 individuals (30 in each group). Patients with systemic vasculitis had elevated EMVs, higher levels of C5b-9 [536.4(463.4) vs 1200.94457.3), p = 0.003] and C1q [136.2(146.5 vs 204.2(232.9), p = 0.0129], compared to controls [232.0 (243.5) vs 139.3(52.1), p < 0.001]. In multivariate analysis both EMVs and C5b-9 were independently associated with disease duration (p = 0.005 and p = 0.004 respectively), yet not with disease activity.

Conclusion

Patients with systemic vasculitis exhibit impaired endothelial function and complement activation, both assessed by easily accessible biomarkers, even in the absence of cardiovascular disease manifestations. EMVs and soluble complement components such as C5b-9 and C1q could be used as early biomarkers of endothelial dysfunction and complement activation, respectively, in clinical practice during the course of SV, yet their predictive value in terms of future cardiovascular disease warrants further verification in appropriately designed studies.

Neoadjuvant targeting of tumor angiogenesis has been developed and approved for the treatment of malignant tumors. However, vascular disruption leads to tumor hypoxia, which exacerbates the treatment process and causes drug resistance. In addition, successful delivery of therapeutic agents and efficacy of radiotherapy require normal vascular networks and sufficient oxygen, which complete tumor vasculopathy hinders their efficacy. In view of this controversy, an optimal dose of FDA-approved anti-angiogenic agents and combination with other therapies, such as immunotherapy and the use of nanocarrier-mediated targeted therapy, could improve therapeutic regimens, reduce the need for administration of high doses of chemotherapeutic agents and subsequently reduce side effects. Here, we review the mechanism of anti-angiogenic agents, highlight the challenges of existing therapies, and present how the combination of immunotherapies and nanomedicine could improve angiogenesis-based tumor treatment.